Compared with other types of display devices (for example, liquid crystal display units), as next-generation displays, OLED display devices may be extensively studied and preliminarily used due to their advantages of light and thin features, low power consumption, high contrast ratio, high color gamut and so on. Compared with liquid crystal display devices, another advantage of the OLED display devices is that the OLED display devices do not need back lighting.
However, a disadvantage of the OLED display devices consists in sensitivity to air and humidity. A majority of organic substances of an OLED light emitting layer are very sensitive to pollutants, O2 and water vapor in the atmosphere, which may directly cause problems such as deterioration of organic light-emitting materials, decrease of a luminous efficiency, abnormal light emission or failure in light emission, and also may cause oxidation and corrosion of metal electrodes. Therefore, packaging technologies have a direct effect on stability and life span of the OLED display devices.
At present, a cover plate being additionally mounted on a backplate may be used for packaging an OLED display device, and generally resin or glass cement and so on may be used to bond the backplate and the cover plate, but the packaging effect is not ideal.